Restrict Numeric Input

jQuery Only digits and point input Max digits number after point

HTML

<h4>Digits Input</h4>
<div>Only digits input (maximum 2 digits after decimal point, decimal separator '.')</div>
<input id="Total" type="number" />
<div>Only digits input (maximum 3 digits after decimal point, decimal separator ',')</div>
<input id="Total2" type="number" />
<div>Only digits input (only positive natural numbers)</div>
<input id="Total3" type="number" />

JavaScript

DigitsInputHelper("#Total", 2, '.');
DigitsInputHelper("#Total2", 3, ',');
DigitsInputHelper("#TotalNotExist", 2, '.');
DigitsInputHelper("#Total3", 0, '.');

/* Allows only digits and one point input, restrics length of mantissa */
function DigitsInputHelper(inputSelector, mantissaLength, decimalSeparator) {
    if ($(inputSelector).length > 0) {
        BindKeyPressUpEvents();
        return $(inputSelector);
    } else {
        return [];
    }

    var valueBeforeKeyEnter;

    function BindKeyPressUpEvents() {
        $(inputSelector).keypress(function (e) {
            var code = e.keyCode || e.which;

            if (GetNumberOfDigitsAfterPoint($(this).val()) <= mantissaLength)
                valueBeforeKeyEnter = $(this).val();

            // allowed key codes
            if (code == 8
                || code == 9
                /*|| code == 37 // '%' */ 
                /*|| code == 39 // ''' */)
                return;

            // only digits
            if (mantissaLength == 0 && (code < 48 || code > 57)) {
                e.preventDefault();
            }
            // NOT allowed key codes
            if ((code != 44 || $(this).val().indexOf(decimalSeparator) != -1
                || decimalSeparator != ',')
                && (code != 46 || $(this).val().indexOf(decimalSeparator) != -1
                || decimalSeparator != '.')
                && (code < 48 || code > 57)) {                 // not number
                e.preventDefault();
            }
        });
        $(inputSelector).keyup(function (e) {
            var inputValue = $(this).val();

            if (GetNumberOfDigitsAfterPoint($(this).val()) > mantissaLength)
                $(this).val(valueBeforeKeyEnter);
        });
    }

    function GetNumberOfDigitsAfterPoint(number) {
        var patternDigitsAfterDot = 
            new RegExp("\\" + decimalSeparator +"\\d*");

        if (number.indexOf(decimalSeparator) == -1) {
            return 0;
        } else {
        ...